The picture shows midsagittal confocal sections of two embryos at late syncytial blastoderm (nuclear cycle 14), the upper stained for bicoid mRNA, the lower for Bicoid protein. The concentration gradients of the mRNA and protein are obvious and very similar (cf. color scale at right). Also evident is that the protein is largely nuclear while the mRNA is restricted to the cytoplasmic perinuclear space of the cortex. The picture was taken by Stefan Baumgartner. See also Spirov, A., Fahmy, K., Schneider, M., Frei, E., Noll, M., and Baumgartner, S. (2009). Formation of bicoid morphogen gradient: an mRNA gradient dictates the protein gradient. Development 136, 605-614.